CREATING VISUAL AIDS AND INTERACTIVE GEOLOGIC MAPS USING VIRTUAL GLOBES

Recent advances in computer-aided mapping technologies have facilitated a dramatic transition from standard two-dimensional (2-D) geologic maps to interactive three-dimensional (3-D) maps with linked databases. The best known digital mapping genre, Geographic Information Systems (GIS), incorporates mapping and visualization abilities beyond 2-D and allows users to toggle multiple layers of data, zoom in and out while recalculating resolution, whilst retaining a database of raw data points from original field work. Unfortunately, the industry standard, ArcGIS, is expensive and thus inaccessible to many users, and only exports 2-D maps unless the user has compatible 3-D software. Our approach overcomes these obstacles by exporting ArcGIS data into a virtual globe (Google Earth) to utilize original 3-D field data to build interactive geologic maps. We created digital maps in ArcGIS, based on fieldwork in two localities from Western Ireland, and exported these maps into Google Earth. The maps recorded the boundaries and orientations of lithologic units, based on original point data. The resulting Google Earth maps have the following features: zoom in/out, pan, full 3-D view, lithologic unit boundaries, three-dimensional strike-dip data, aerial photo overlays, toggle-able layers, structural feature data, and lithologic unit boundaries. Additional features beyond the parameters of 2-D maps include detailed outcrop notes linked to individual locations, and cross-sections that emerge from the globe's surface in the appropriate locations. Features currently being developed include the insertion of paleo-topography to show ancient tectonic environments and reconstructions to allow the world's continental landmasses to be viewed in their ancient positions. Future plans involve the development of free and user-friendly templates to allow other researchers to easily build Google Earth-based interactive geologic maps from their own field data.

Google Earth-based geologic maps provide users with more information, including access to raw field data and integrated cross-sections, as compared with classical 2-D maps. However, we maintain that the most important of Google Earth's features is the intuitive interface that encourages interactive, user-centered investigation.